Coil assembly for transformers



Feb. 23a 1932. R. A. FINNEGAN 1,346,801.

COIL ASSEMBLY FOR TRANSFORMERS Filed July 6, 1931 2 Sheets-Sheet l Home@A. mme-Gnu.

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Feb. 23, 1932.

yR. A. FlNNEGAN COIL ASSEMBLXl FOR TBANSFORMERS Filed July .6, 1931 2Sheets-Sheet 2 ,BVMW

QTTOEN/SY v.RICHARD A. FIN N EGAN, 0F

Patented Feb. 23, 1932 UNITED STATES TRIO COMPANY, OF

PATENT OFFICE A CORPORATION OF DELAWARE COIL ASSEMBLY FOR TRANSFORMERSApplication led July 6,

This invention relates to transformer coils of the type commonlyreferred to as twin coils, double section coils or back turn coils,which consist of two coil sections joined together and arranged insuperimposed relation or in longitudinal alignment with each other, andan annular-shaped insulating barrier interposed between said coilsections and combined with same in such a way as to form a unit whichcan be handled easily in the operation of stacking up the coils of atransformer.

In the conventional twin coil or double section coil, Vthe two sectionsof the coil are clamped to the barrier between the same by tape that iswound spirally around the three elements and which extends over theouter sides of the coil sections and around the inner and outer edges ofthe barrier. The above described method of binding or clamping the coilsections to the barrier is objectionable for numerous reasons:

1) It is costly, on account of the time involved in wrapping a tape orstrand spirally around the three elements of the structure;

(2) It tends to retard the escape of heat from the coil, due to the factthat the outer Sides of the coil sections are practically coveredthroughout the major portion of their areaby tape;

(3) It does not insure the coil sections being maintained in absolutelyconcentric relationship with the barrier with the inner edges of thecoil sections extending iiush with the inner edges of the barrier; and c(4) It produces a coil assembly of crude and unworkmanlike appearance,for after a number of coil assemblies have been stacked up or arrangedin superimposed relation, and the stack subjected to endwise pressure,the portions of the tape that extend over the outer edges of thebarriers become slack, thereby greatly detracting from the appearance ofthe coll stack and also making it possible for the barriers to shifthorizontally to such an extent that they do not project laterally therequired distance beyond the outer edges of the coil sections.

The objects of my invention are to reduce the cost of manufacturing orproducing 1931. Serial No. 548,756.

transformer coil assemblies of the general type referred to eliminatethe possibility of the barrier of a double section coil or twin coilshifting relatively to the two sections of the coil; improve the heatradiating properties of a double section coil or t\ in coil by reducingthe quantity of tape` or other material that is used to combine thesections of the coil with the barrier; and eliminate the possibility ofthe binding tape becoming slack or bulgy after the coil assembly hasbeen installed or arranged in superimposed relationship with other coilassemblies in the transformer.

To this end I have devised a twin coil, double section coil or back turncoil in which the two sections of the coil are combined with or clampedto an annular-shaped insulating barrier interposed between the coilsections, by means of a few strands of tape or other suitable materialdisposed so that they clamp or bind the coil sections to the barrier andhold the inner edges of the coil sections flush with the inner edge ofthe barrier, without crossing the outer edge of the barrier thatprojects laterally beyond the outer edges of the coil section. Thenumber of strands that are used will depend upon the size of the coil,but usually four or five strands will be sufficient for a small coil andseven or eight strands will be suiiicient for a large coil. Said strandscan be arranged in various ways without departing from the spirit of myinvention, but usually the strands will be so arranged that each strandcomprises two legs or portions that lead outwardly from the inner edgeof the barrier and then around the coil sections in such a manner thateach strand not only draws the two coil sections into intimateengagement with the barrier, but also exerts pressure on said coilsections in a direction that practically eliminates the possibility ofthe inner edges of the coil sections moving out of alignment with theedge of the center opening of the barrier.

Figure l of the drawings is a top plan View of a transformer coilassembly embodying my invention.

Figure 2 is a vertical sectional view, illusprefer to sides ot thebarrier.

a way that the barrier trating a plurality of my improved coilassemblies, stacked up or arranged in superimposed relation; and

Figures 3, A, 5 and 6 are diagrammatic views, illustrating the varioussteps in the operation ot assembling or combining the coil sections withthe barrier.

In the drawings A and A designate the two sections ot a twin coil,double section coil or. back turn coil, and B designates anannular-shaped insulating barrier interposed between said coil sectionsand arranged in such relationship with the same that the inner edge otthe barrier will extend flush with the inner edges ot the coil sectionsand the outer edge of the barrier will project laterally beyond theouter edges ot the coil sections.Y The coil sections A and A bound uponthe barrier B by means ot a plurality of strands C formed preferablyfrom pieces of linen tape or other non-metallic, pliable material thatis looped around the coil sections and arranged in engagement with thebarrier in such a way that strands securely clamp'said three elementstogether and hold f them in concentric relationship without crossing theouter edge ot the barrier, or, in other words, without causing portionsof the strands C to extend trom the outer edges of the coil sectionsover the outer edge of the barrier. As previously stated, the number otstrands or tapes C that are used with each coil assembly will dependupon the size or diameter of the coil sections A and A.

In producing my improved coilassembly l iirst pass a strand C throughthe center opening ot the barrier B and double or told said strand insuch a way that the strand comprises an anchoring portion orintermediate `portion that engagesl or bears upon the inner edge of thebarrier, and two legs y and e that lead outwardly from said anchoringportion 'w over the top and bottom rIhe two coil sections A and A arethen applied to the barrier in such will lie between said coil sectionswith the inner edge ot the barrier inA alignment with or extending flushwith the inner edges of the coil sections, and with the outer edgeportion of the barrier projecting laterally beyond the outer edges ofthe coil sections, as shown in Figure 3. For convenience l willhereinafter refer to the coil` section A as the'topsection and the coilsection A as the bottom section. The twolegs y and c of the 'strand Care then drawn over the outer edges ofthe coil sections and leadinwardly to the inner edges of the said coil sections. One of said legs,for example, the leg y that embraces or surrounds the top coil sectionA, is then inserted between the underside ot the barrier and the toptace ot the bottom coil'section A by means ot a tool or instrumentprovided with a fiat, blunt blade l, as shown in Figure t, the blade lbeing moved are clamped to orv outwardly towards the outer edge of thebarrier, i. e., to the right, looking at Figure A, so as to cause theleg y to be positioned between the barrier and the bottom coil sectionA', as shown in Figure 5. in the same way the leg e, which surrounds orembraces the bottoni coil` section A', is arranged between the top sideot the barrier and the top coil section A; lWhen the two legs y and eare drawn tight, the leg y will exert pressure on the top coil section Ain a direction tending to clamp said top coil section to the barrier,and the leg a will exert pressure on the bottom coil section A in a`direction tending to clamp said bottom coil'section to the barrier. Inaddition to drawing the coil sections into intimate engagement with thebarrier, the operation ot drawing the legs f/ and a tight causes the twocoil sections to be centered with relation to the barrier B, due, ofcourse, to the fact that the strand C is anchored on the inner edge otthe barrier, so that when the two legs y and .a are pulled tight, saidlegs will exert an inward lateral thrust orcross-wise thrust on the coilsections, and edges ot said coil sections to line up with the inner edgeof the barrier or the point of anchorage ot the strand C. The iinal stepin the operation of installing the strand C is to drawV the leg y overthe outer edge of the bottom coil section A', and thence inwardly acrossthe underside of the coil section, and draw the leg .e over the outeredge of the top coil section A, and thence inwardly over the top face ofsaid coil section A. rlhe same procedure` is employed to install theother strands used to bind the two sections A and A ot the coil to thebarrier B. VAt some pointV in the assembling operation the treeendsoithelegs 'y and .e of each strand are secured preferably by tyingthem together so as to form a knot w, as shown in Figure 6, which knotis arranged on the inside ot the structure where it will be hidden fromview when the coil assembly is arranged in superimposed relationshipwith other coil assemblies sogasV to torni a coil stack.

With the coil assembly ot above described the operation lot exertingendwise pressure on a' stack of coils so as to clamp them together, hasabsolutely no effect on the tapes or strands C used to bind the sectionsot each coil to its interposed barrier, due, of course, to the Jr'actthat the tapes are anchored on the inner edge of the barrier, from whichpoint the tapes are V coils, and thence baclrto the inner edge of thebarrier. The result is that a coil stack, made up ot coil assemblies ofthe kind above described, will present a workmanlike appearance, with.no loose or bulgy tapes. the m'ain radvantages oi' my coil assembly,however, is that it is impossible torthe barrier to shift horizontallyrelatively to the coil sections and'become arranged in such apositionthus cause the inner the construction i drawn taut around the' f One otiii that the barrier does not project laterally suiliciently beyond theouter edges of the coil sections to perform the function for which thebarrier is employed. As the outer surfaces of the coil sections arecovered by only a relatively few strips of tape, heat can radiate fromthe coil easily, and still another desirable feature of my coilassembly, is that the coil sections can be bound to the barrier in afraction of the time required to wrap a tape spirally around two coilsections mounted on a barrier, thereby greatly reducing the cost ofmanufacturing a twin coil, double scction coil or back turn coil.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent is:

1. A coil assembly for transformers, consisting of a double sectioncoil, an annularshaped barrier interposed between the two sections ofthe coil, and strands for holding said elements in assembled relation,disposed' so that said strands surround the coil sections withoutcrossing the outer edge of the barrier.

2. A coil assembly for transformers, consisting of a double sectioncoil, an annularshaped barrier interposed between the twosections of thecoil, and strands for holding said elements in assembled relation,disposed so that said strands exert pressure on the coil sections in adirection tending to hold the inner edges of the coil sections flushwith the inner edge of the barrier.

3. A coil assembly for transformers, consisting of a double sectioncoil, an annularshaped barrier interposed between the twosections of thecoil, and strands for holding said elements in assembled relation,disposed .so that each strand draws both coil sections towards thebarrier and also exerts pressure on said coil sections in a directiontending to hold the inner edges of same flush with the inner edge of thebarrier.

4. A coil assembly for transformers, consisting of a double sectioncoil, an annularshaped barrier interposed between the two sections ofthe coil and arranged so that its outer edge projects laterally beyondthe outer edges of the coil sections, and strands for maintaining thecoil sections in assembled relationship with the barrier, located whollyinside of the outer edge of the barrier.

5. A coil assembly for transformers, consisting of a double .sectioncoil, an annularshaped barrier interposed between the two sections ofthe coil, and strands for clamping the coil sections to the barrier,each of said strands being arranged in engagement with the inner edge ofthe barrier and comprising portions that are looped around the coilsections.

y6. A coil assembly for transformers, consisting of a double sectioncoil, an annularshaped barrier interposed between the two sections ofthe coil, and strands for clamping the coil sections to the barrier,each of said strands being arranged in engagement with the inner edge ofthe barrier and comprising portions that are looped around the coilsections a plurality of times.

7 A coil assembly for transformers, comprising two coil sectionsarranged in superimposed relation, an annular-shaped barrierinterposed'between said coil sections, and a strand stretched across oneedge of said barrier and provided with legs that exert pressure on thecoil sections in two directions at right angles to each other, wherebythe coils are clamped' to the barrier and maintained in concentricrelationship with the barrier.

8. A coil assembly for transformers, comprising two coil sectionsarranged in superimposed relation, an annular-shaped barrier interposedbetween said coil sections, and a strand stretched across one edge ofthe barrier and provided with legs, each of which is looped around bothsections of the coil without crossing the other edge of the barrier.

9. A coil assembly for transformers, comprising two coil sectionsarranged in longitudinal alignment with each other, an annular-shapedbarrier interposed between said coil sections, and a strand disposedcrosswise of the inner edge of the barrier and looped around said coilsections, the free ends of said strand being secured together adjacentthe center of the structure.

10. A coil assembly for transformers, consisting of a double sectioncoil, an annularshaped barrier interposed between the two sections ofthe coil, and strands for binding said coil sections to the barrier,disposed so that each strand comprises an intermediate portion anchoredon one edge of the barrier, and two separate legs wrapped around thecoil sections without crossing the other edge of the barrier and havingtheir free ends tied together.

11. A coil assembly for transformers, consisting of a double sectioncoil, an annularshaped barrier interposed between the two sections ofthe coil, and strands for holding the coil sections in assembledrelationship with the barrier, each of said strands comprising ananchoring portion that contacts with the inner edge of the barrier andtwo leg portions disposed so that each leg portion exerts pressure onboth coil sections in a direction tending to clamp the same barrier andmaintain said sections in concentric relationship with the barrier.

12. A coil assembly for transformers, consisting of an annular-shapedbarrier, two coil sections arranged at opposite sides of said barrier inconcentric relationship with the same, a strand for holding saidelements in assembled relationship, provided with an intermediateportion that engages the inner edge of the barrier, and two leg portionsthat lead outwardly to the outer edges of the coil to the f Sections,one of Said leg .portions extending inwardly over the top coil section,thence downwardly tlnough the barrier andV around the bottom coilsection, and said other-'leg portion extending inwardly under` theloottom coil section, thence upwardly through the barrier, andthereafter around the top coil section.

RICHARD A.' FINiJEGrAiTi

